This invention relates to structural systems including interconnected, endwise-aligned elongated members, and to splice members therefor. In a particular sense, the invention is directed to ceiling systems of the type having a grid of horizontally elongated, interconnected support members, some of which are aligned end to end, and to splice members for interconnecting adjacent support members thus aligned.
In present-day building construction, a suspended ceiling of panels or tiles is frequently provided below the structural ceiling of a room, for acoustic or aesthetic reasons or to conceal equipment located in the space between the suspended and structural ceilings. A known type of suspended ceiling includes an assembly of horizontally elongated support members of inverted T cross-section, interconnected to form a rectangular grid and each having a vertical web with opposed longitudinal flanges projecting from the base of the web to support the ceiling tiles. The grid comprises a first plurality of the T members, referred to as runners, disposed in spaced parallel relation to each other and suspended by wires or other means from the building structure, and a second plurality of T members extending in spaced parallel relation to each other transversely between the runners. Each runner may be constituted of two or more individual T members aligned end to end and interconnected by splice members that bridge the joints between them and have horizontally spaced lugs or tabs projecting through openings in the end portions of the T member webs, as shown, for example, in U.S. Pat. Nos. 2,873,828, 2,946,414, and 4,335,973. The transverse T members of the grid may also be aligned end to end on opposite sides of a runner, to or through which they may be interconnected endwise by hooks formed in or connected to the end portions of their webs for projecting through or engaging openings or seats in the runner webs, again as shown for example in the aforementioned U.S. Pat. Nos. 2,873,828, 2,946,414, and in U.S. Pat. Nos. 3,093,221, 3,096,862, and 3,187,856.
Splice members heretofore used or proposed for endwise interconnection of runner members have generally been more or less difficult to produce and/or complex to install. Additionally, they afford only relatively weak resistance to forces tending to pull the spliced runner members apart longitudinally. Transverse T member connecting means of known types are also vulnerable to disengagement when subjected to forces acting longitudinally of the connected T members. Such forces, as may be exerted on ceiling grids during earthquakes, can cause the T members of conventional grids to separate from each other, with resultant destructive damage to the ceilings and serious hazard of injury to persons or objects beneath. Accordingly, in some earthquake-prone regions, governmental regulations specify minimum requirements of strength (i.e., resistance to longitudinally directed separating forces), for connections between members of a ceiling grid, that have necessitated resort to special and costly expedients detracting from desired ease, convenience and economy of suspended ceiling construction.